Do you want a game or a movie as your desktop background? Read this article!
Step 1. Find the flash file (.swf) that you want to make your desktop background
Step 2. On the page where you found the game or movie, look at the source code of the page and find ".swf" without quotes in it
Step 3. When you find it, paste it into the address bar
To save it, click on the "File" menu of your browser and select "Save Page As".